Removable oven dook assembly



March 3, 1964 o. E. HAR'rsoN REMOVABLE OVEN DOOR ASSEMBLY 2 Sheets-Sheet 1 Filed April 27, 1961 flNl/ENTOR OLIVER E. HARTSON ATTORNEYS United States Patent C) M 3 123 054 nnmovanrn oven noon Assnnrsiv @liver E. Hartson, Mansfield, Ohio, assigner to The Tappan Company, Mansfield, Ohio, a corporation of @hie Filed Apr. 27, 1961, Ser. No. 196,139 Claims. (Cl. 126-191) This invention relates to a removable door for a cooking oven and, more particularly, to improvements in the closure mechanism of this type disclosed in U.S. Patent No. 2,721,547, issued October 25, 1955.

The oven assembly of said patent comprises a door movable between vertical closed and substantially horizontal open positions on hinge members at its lower corners, with the latter including slotted brackets secured at the lower front of the oven and door-carried pins pivoted in the same. A cam in the form of an arm of special configuration extends inwardly from adjacent each side of the door normally into engagement with a roller on a fixed axis at the exterior of the corresponding side of the oven. Such cams are pivoted at the inner face of the door and have extensions connected to counterbalance springs housed Within the door structure, with the cams passing under the respectively associated rollers and urged against the same by the springs. The latter countervbalance the door in all positions, while the cams are additionally formed to hold the door in its substantially horizontal open position, for example, by terminal hooks which engage about the rollers when the door is in such position.

' It will' be appreciated from even this brief description of the prior assembly that removal of the door requires some means for locking the counterbalance springs in inoperative condition, thereby to free the cam arms, and the patent discloses several latch expedients for the purpose. These are all, basically, hand-actuated detents operative to restrict relative swinging of the arms on their pivotal connections to the door by interposition thereof between the door and the cams transversely to the latter and at the spring sides of the cam pivots. According to one proposal, such latching is accomplished by means of separate pins inserted transversely through the cams in the indicated arrangement to bear against stationary surfaces at the inside of the door; the pins can be thus inserted freely when the door is substantially fully open and slight movement to closure causes the projecting ends of the pins to act as stops effective to lock the cams against further relative movement in this closing direction. With ie thus restrained cams now at a fixed angle, the door 'can be lifted from its hinge mounting and the cams cleared and withdrawn from the rollers.

While the closure mechanism employing latch pins as aforesaid has been used on ranges for some time, this use does require a housewife to keep the two pins on hand with some attention to their storage when not in use to protect against misplacement or loss of the same. The insertion of the pin in its hole in the cam is, moreover, an operation which apparently a housewife would prefer to accomplish in most cases with her favored hand, with the two pins thereby being inserted successively, rather than simultaneously. When the door is re-installed, the manipulations are of course reversed, with the latches not only moved by hand to operative condition but requiring withdrawal or release also by hand. While the noted patent further discloses latches normally carried by the door, that is, without separation as in the caseV of the pins, such further expedients similarly require direct manual release in addition to the hand actuation to the locking condition.

lt is a primary object of the present invention to provide an improved form of such closure mechanism which ddd Patented Mar. 3, 199% ICC permits quicker and more convenient removal of the door.

Another object is to provide a removable oven door assembly of this type utilizing contained, i.e., non-sep- V arable, latch means for disabling the counterbalance mechanism of novel and improved construction and operation.

It is a further object of the invention to provide latch means in such an assembly which can readily be operated by either hand, whereby it is possible conveniently to operate both of the two needed latches simultaneously.

An additional object is to provide such an assembly in which the latch means can be adjusted to operative or active condition by a single linger and is automatically withdrawn in normal re-installation of the removed door without further direct manipulation of such latch means.

Other objects and advantages of the present invention will become apparent as the following description proceeds.

To the accomplishment of the foregoing and related ends, the invention, then, comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawings setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principle of the invention may be employed.

ln said annexed drawings:

FG. 1 is a fragmentary vertical section of an oven door assembly in accordance with the present invention, the section thereof being indicated by the line 1-1 in FIG. 4;

FlG. 2 is a similar section showing the door in its open position;

FIG. 3 is a similar view with the door partially open and in condition for removal from the oven;

FIG. 4 is a fragmentary sectional View taken on the line 4 4- in FlG. 1; and

FIG. 5 is a fragmentary horizontal section the plane of which is indicated by the line 5 5 in FIG. 1.

Referring now to the drawings in detail, the illustrated structure occurs at the lower right front corner region of an oven assembly comprising a cooking compartment and a door therefor designated generally respectively by reference numerals 10 and 11. In this area, the oven comprises a bottom 1.2, an inner side wall 13, and a front frame or wall 14, the latter being about the open front of the compartment. There is an outer side wall 15 (FIG. 5) spaced from the wall 13 and accordingly delining a chamber 16 therewith immediately outside the oven compartment.

The portion of the door `11 which has been shown similarly constitutes the lower right corner portion of the same or that pontion which cooperates with the illustrated oven structure. Such door is of the usual hollow form, with inner and outer liners 17 and 13 respectively having opposed and overlapping peripheral iianges. At its indicated corner, a spring bracket 19 is rigidly mounted within the door, such bracket here being shown as having pads 2@ attached by screws to supports 21 secured to the inside surface of the outer door liner 18. The main portion of the bracket is elongated, of general U-shape in cross-section, and extends along this side 22 of the door, with one end closely adjacent the door bottom 23. With further regard to its section, the bracket is open outwardly, that is, toward the outer door liner 18, and there is an integr-al third wall portion 24 in outwardly spaced parallel relation to the main section at the lower inner end of the same. Such wall portion 24 and the opposed wall portion of the main section of the bracket support a transverse pivot pin 2S, arid a slot -26 is provided in the inner door liner 17 and around the bottom 23 of the door for engagement of such pin in a hinge bracket 27 secured to the front frame or wall 1- at `a point below the oven compartment bottom 12 and slightly outboard of the inner side wall 13 of the same.

The hinge bracket 27 is formed with a forwardly pro- ]ecfting ear 2S having a downwardly and inwardly inclined slot 29 therein terminating in a seat 39. The forwardly projecting ear 2S is accommodated in the door slot Z6 and receives the door pin 25 in its seat 3h to proiide a hinge connection of such corner portion of the oor.

The spring bracket 19, at its upper half, is provided with a slot 31 in its inner Wall, which is the base of its main channel section, and integral semi-circular sections 32 project in spaced parallel relation from the respective sides of such slot through an opening 33 provided in the inner door liner 17, whereby such projecting sections are exposed at the inside of the door. There is an integral bridge 3d between the sections 32j at the upper extremities of the same for a purpose to be described.

A pivot pin 3S is supported transversely by the semicircular projecting sections to provide a horizontal pivot spaced slightly from the inner door liner, and a curved cam 36 is pivoted thereon. Such cam is provided with a slot 37 relatively close to one end in which the pivot pin 3S is received and Ithe short arm 3S of the cam passes through the bracket slot to the interior of the door. One end of a coil spring 39 is hooked on the inner end of the cam arm 38, at 4t), and the other end of the spring is engaged by a holding screw 41 passing through an end flange 42. of the bracket 19. The latter is just inside the bottom 23 of the oven door, where an opening d3 is provided for access to the head of the spring holding screw 41. The turns of the spring at such end are reduced tor threaded engagement of the screw 'therein and accordingly the screw can ybe actuated to adjust the spring tension.

The long arm d of the cam 36, extending outwardly from the pivot connection 35 to the door, curves upwardly and terminates in a free end hook 4'5. This arm of the cam enters a slot 46 provided in the front wall or frame 14 and engages under a roller 47 mounted on a bracket 4S fixed within the chamber 16 between the inner `and outer oven walls 13 and i5. lt will be observed that the spring 39 normally urges the cam arm d4 against the roller 47, and that the terminal hook 45 serves to hold the door in its fully open substantially horizontal position. Such arm is also provided with a depression 49, near its pivot 35, for seating of the roller therein when the door is fully closed for positive holding of the same -in this position. The contour of the upper edge of the cam arm 44 is such that the counterbalancing of the door provided by the spring progressively varies during opening and closing of the `door to compensate for variation in the force exerted 4by gravity. The spring force is accordingly at a minimum when the door is closed and at its maximum when the door is fully open.

As explained earlier, and as now will be apparent, the counterbalance spring 39 must be locked in inoperative condition to permit removal of the door, and a U-shaped catch designated generally by reference numeral Si? carried by the cam arm itself is employed for this purpose. Such catch comprises spaced parallel wings 51 of particular shape and an integral bridge 52. It is pivoted on a raised upper edge portion 53 of the cam 36, adjacent the pivotal connection 35 of the latter to the spring bracket 19, by means of a pin 54 passed transvertsely through such raised portion of the :arm `and the Wings 5,1 of the catch intermediate the ends of the latter. The catch is thus disposed with its wings at the respective side faces of the cam, and there is enough friction in the attachment to maintain the catch in selected rotative positions of adjustment relative to the cam.

The normal condition of the catch 59 is shown in FIG. 1 and, in this relative position, the illustrated wing contigui-ation is such to permit the catch to move freely in and out of the slits 31 and 33 respectively in the spring bracket 11 and the inner door liner 17. Accordingly, the thus positioned catch has no etect on operation of the counterbalance mecahnism. The wings 51 of the catch are formed to define, preceding from the end bridge portion 52, arcuate sections 55, notches v56, and terminal sections 57 of general rectangular shape which are, moreover, extended outwardly relative to the arcuatey sections.

When the door is in a given intermediate position wherein the arcuate sections 55 just emerge from the slot 31, shown by the dashed outline in FIG. 2, the catch 50 can be rocked on its pivot 54 relative to the cam 36 by pressing on the bridge 52 with a finger inwardly or in the direction indicated. By thus holding the catch down while permitting the door to move from the temporarily arrested position upwardly or in the direction of closing, the wings 51 are elfectively extended to bring the ends of the arcuate sections 55 at the notches S6 out into the path of the bridge 34 at the upper end of the spring bracket slot 31. This bridge 34 thereby abuts such notch edges of the catch sections 55, and the cam 36 is accordingly locked as shown in FIG. 3 against further pivoting by the spring in the normal direction upon further closure of the door. The door in FlG. 3 has actually been moved beyond the locking angle to show how the now xed cam 36 is withdrawn from the roller 47 as the result of such restraint of the former. Y

It will also be noted that the catch bridge 52 bears substantially fully against the raised cam portion 53 when the catch is locked or effectively braced between such contact and the spring bracket 1%. The door can now be simply lifted to remove its pivot pin 25 from the hinge bracket 2.7 and the cam arm 44 is withdrawn through the frame slot 46.

In replacing the door, the cam arm 44 is inserted in the frame slot 46 under the roller 47 and the hinge pivot n 25 seated in the hinge bracket 27. The door is then swung downwardly or toward open position and just after passing through the angle at which the catch was set, the terminal extensions 57 of the wings 51 are engaged by the underside of the spring bracket bridge 34 and such extensions are cammed inwardly with continued movement of the door in this direction to retract the catch automatically to release position shown in FIG. 1, whereupon the door can be closed and opened without further interference. That is, manipulation of the door alone as stated accomplishes the release of the catch, eliminating any need for direct hand movement of the same for the purpose.

Accordingly, while the counterbalance mechanism is locked manually, the operation is extremely easy to perform and the release is effected by movement of the door rather than the catch itself, with the former obviously being much more convenient than the latter.

The structure described is duplicated at the other lower corner of the oven and door, and it is not deemed necessary to repeat the foregoing speciiically for such other corner. It will be readily understood that the full mounting of the door would thus comprise two hinge and counterbalanced cam mechanisms and, moreover, that both catches in such assembly can very easily be set simultaneously. The job of removing the door for the usual purposes of cleaning and the like is greatly facilitated on this account, while the re-mounting of the door in the manner described effects release of both of the catches at the same time.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims or the equivalent of such be employed.

I, therefore, particularly point out and distinctly claim as my invention:

l. In combination with an oven door, counterbalance mechanism comprising an elongated cam, means for pivotally mounting said cam at a side of the door for relative swinging movement in a plane normal to the plane of the door, spring means for biasing the thus mounted cam in one direction, latch means carried by the cam at a portion thereof exposed at said side of the door and being adjustable thereon between first and second positions, the latch means in said first position being relatively retracted and in the second position bearing against a stop surface on the cam and extending relatively therefrom beyond the leading edge of the cam in the movement of the latter in said one direction, and stationary stop means carried by the door adjacent the path of movement of the earn for engagemeA t with the latch means when in said second position thereof, the stop means and the stop surface of the cam acting oppositely on the latch means to lock the cam against movement thereof by the spring means in said direction beyond a predetermined point, thereby to lock the counterbalance mechanism in an inoperative condition, the latch means in its relatively retracted first position of adjusment being freely movable with the cam past the stationary stop means.

2. ln combination with an oven door having a chamber therein, counterbalance mechanism comprising elongated cam means extending outwardly from within the door chamber through a side opening provided therefor, pivot means for supporting the cam means for swinging movement relative to the door in such disposition of the former, with said pivot means spaced from the end of the cam means within the door chamber, spring means in said chamber and connected to such end of the earn means for biasing the same in a first direction about the axis of the pivot means, and latch means carried by and being adjustable on a portion of the cam means adjacent said side of the door, said latch means being normally relatively movable with the cam means freely through the side opening and manually adjustable to a locking position in which it extends over the end of the opening near the leading edge of e cam means when the latter moves relatively in said rst direction, with the latch means being thus adjustable to such locking position after predetermined relative movement of the cam means opposite to said first direction for limiting full spring return thereof in the rst direction.

3. ln combination with an oven door having a chamber therein, counterbalance mechanism comprising elongated cam means extending outwardly from within the door charnber through a side opening provided therefor, pivot means for supporting the cam means for swinging movement relative to the door in such disposition of the former, with said pivot means spaced from the end of the cam means within the door chamber, spring means in said chamber and connected to such end of the cam means for biasing the same in a first direction about the axis of the pivot means, latch means carried by and being adjustable on a portion of the cam means adjacent said side of the door, said latch means being normally relatively movable with the cam means freely through the side opening and manually adjustable to a locking position in which it extends over the end of the opening near the leading edge of the cam means when the latter moves relatively in said first direction, with the latch means being thus adjustable to such locking position after predetermined relative movement of the cam means opposite to said first direction for limiting full spring return thereof in the first direction, and means for camming the latch means from the locking position to the normal position of the same in response to further relative movement of the cam means opposite to the first direction beyond the point at which the latch means was adjusted to the locking position.

4. An oven assembly comprising means including a front wall defining an oven compartment open at the front, a door at the front of said compartment for closing the same, hinge means for removably securing said door to the front wall for swinging movement between vertical closed and substantially horizontal open positions, counterbalance means for the door including first cam means in fixed spaced relation to the hinge mounting of the door,

cooperable second cam means having in one condition a pivotal connection to the door and extending to one side from said pivotal connection between the rst cam means and the hinge means, spring means connected to the second cam means at the other side of the pivotal connection thereof and operative to bias the same resiliently away from the hinge means and accordingly against the first cam means, manually settable latch means for locking the counterbalance means in an inoperative condition for removal of the door, said latch means being operative when setto limit the relative movement of the second cam means under the influence of the spring means at predetermined partial closure of the door for ready disengagement from the first cam means, and means for releasing the set latch means in response to swinging of the door on the hinge means in the direction of opening beyond the position for setting of the latch means.

5. An oven assembly as set forth in claim 4 wherein the latch means is mounted on the second cam means for movement therewith and limited movement relative to the same.

6. An oven assembly as set forth in claim 5 wherein the latch means is pivoted on the second cam means, and the manual setting of the same causes a normally retracted portion to extend for abutment with a stop surface.

7. An oven assembly as set forth in claim 4 wherein the door has a chamber-ed portion within which the spring means is housed, the second cam means projects therefrom to the inside of the door, and the latch means is mounted on the second cam means with at least a portion exposed for access at the inside of the door.

8. An oven assembly as set forth in claim 7 wherein stop means is provided adjacent the inner side or the door, and the latch means is adjustable relative to the second cam means to extend therefrom into engagement with said stop surface.

9. An oven assembly as set forth in claim 11 wherein the latch means has an extension which is moved behind the stop means when the latch means is setto locking condition, and the relative movement of the second cam means upon opening of the door beyond the angle for setting of the latch means causes the stop means to engage said extension and cam the latch means to a retracted position with respect to the stop means.

10. An oven assembly comprising means including a front wall defining an oven compartment open at the front, a door at the front of said compartment for closing the same, hinge means for removably securing said door to the front wall for swinging movement between vertical closed and substantially horizontal open positions, counterbalance means for the door including restraining means in fixed spaced relation to the hinge mounting of the door, lever means carried by the door and engaged with said restraining means, spring means within the door connected to said lever means and resiliently biasing the same into engagement with the restraining means, manually settable latch means for locking the counterbalance means in an inoperative condition for removal of the door, said latch means being operative when set to limit movement of the lever means under the influence of the spring means at predetermined partial closure of the door for ready disengagement from the restraining means, and means for releasing the set latch means in response to swinging of the door on the hinge means in the direction of opening beyond the position for setting of the latch means.

References Cited in the file of this patent UNlTED STATES PATENTS 2,208,871 Rogers July 23, 1940 2,721,547 Polluck Oct. 25, 1955 3,040,732 Doner June 26, 1962 3,049,116 Hillebrand Aug. 14, 1962 

1. IN COMBINATION WITH AN OVEN DOOR, COUNTERBALANCE MECHANISM COMPRISING AN ELONGATED CAM, MEANS FOR PIVOTALLY MOUNTING SAID CAM AT A SIDE OF THE DOOR FOR RELATIVE SWINGING MOVEMENT IN A PLANE NORMAL TO THE PLANE OF THE DOOR, SPRING MEANS FOR BIASING THE THUS MOUNTED CAM IN ONE DIRECTION, LATCH MEANS CARRIED BY THE CAM AT A PORTION THEREOF EXPOSED AT SAID SIDE OF THE DOOR AND BEING ADJUSTABLE THEREON BETWEEN FIRST AND SECOND POSITIONS, THE LATCH MEANS IN SAID FIRST POSITION BEING RELATIVELY RETRACTED AND IN THE SECOND POSITION BEARING AGAINST A STOP SURFACE ON THE CAM AND EXTENDING RELATIVELY THEREFORM BEYOND THE LEADING EDGE OF THE CAM IN THE MOVEMENT OF THE LATTER IN SAID ONE DIRECTION, AND STATIONARY STOP MEANS CARRIED BY THE DOOR ADJACENT THE PATH OF MOVEMENT OF THE CAM FOR ENGAGEMENT WITH THE LATCH MEANS WHEN IN SAID SECOND POSITION THEREOF, THE STOP MEANS AND THE STOP SURFACE OF THE CAM ACTING OPPOSITELY ON THE LATCH MEANS TO LOCK THE CAM AGAINST MOVEMENT THEREOF BY THE SPRING MEANS IN SAID DIRECTION BEYOND A PREDETERMINED POINT, THEREBY TO LOCK THE COUNTERBALANCE MECHANISM IN AN INOPERATIVE CONDITION, THE LATCH MEANS IN ITS RELATIVELY RETRACTED FIRST POSITION OF ADJUSTMENT BEING FREELY MOVABLE WITH THE CAM PAST THE STATIONARY STOP MEANS. 